Engineering Commons^™

Microstructural Characterization Of High Velocity Oxy Fuel Coatings Of Inconel 718 And Iron Aluminides, Ana Cecilia Rios Ibanez

Open Access Theses & Dissertations

Thermal spray guns are used today to deposit metallic powders as homogeneous and durable coatings with low porosity onto metals. The objective is to improve their wear resistance and their corrosion resistance in order to withstand conditions such as abrasion and erosion. This can improve the life of turbines, generators and such devices in environments found in ultra-supercritical coal-fired (AUSC) boilers, steam turbines and gas turbines (Mohammed & Cabrera, 2014). Industries like manufacturing, automobile and especially in the sustainable energy area, have used this technique to improve component characteristics, extend product life, increase performance as well as reduce production and …

An Effective And Optimal Quality Control Approach For Green Energy Manufacturing Using Design Of Experiments Framework And Evolutionary Algorithm, Juan Alejandro Saavedra

Open Access Theses & Dissertations

Quality Control (QC) and Quality Assurance (QA) strategies vary significantly across industries in the manufacturing sector depending on the product being built. Such strategies range from simple statistical analysis and process controls, decision-making process of reworking, repairing, or scraping defective product. This study proposes an optimal QC methodology in order to include rework stations during the manufacturing process by identifying the amount and location of these workstations. The factors that are considered to optimize these stations are cost, cycle time, reworkability and rework benefit. The goal is to minimize the cost and cycle time of the process, but increase the …

Development And Testing Of Oxygen/Methane Torch Igniter Technologies For Propulsion Systems, Luis Eduardo Sanchez

Open Access Theses & Dissertations

The development and testing of an oxygen/methane torch ignition system as well as the evaluation process of the system are presented with the purpose of characterizing the properties and performance of methane as a fuel in a propulsion system. The experimental approach to this Dissertation entails the development and testing of a swirl torch igniter under conditions that may be seen when feeding propellant from the main storage tanks: combinations of gaseous and liquid oxygen and methane. The experimental goal of this Dissertation is to display the range of operability of the igniter technology presented leading to stable and consistent …

Investigation On Pyroelectric Ceramic Temperature Sensors For Energy System Applications, Md Rashedul Hasan Sarker

Open Access Theses & Dissertations

Temperature monitoring for energy generation systems plays an important role for control of overall safety and efficiency. To operate the energy system at optimum operating conditions, it is important to measure the real time temperature. Furthermore, harsh environment temperature sensing is desired since most sensors in energy systems are exposed to high temperature, high pressure, and corrosive environments. There is an increasing demand of wireless sensor networks and major interest in energy system applications for harsh environment and remote sensing applications. For this study, LiNbO3 and Pb(Zr0.52Ti0.48)O3 (PZT) pyroelectric ceramic materials were used to develop temperature with wired and wireless …

Removal Of Iron, Zinc, And Copper From Waters Impacted By Acid Mine Drainage Using Natural Zeolite, Mackayla Janae Thyfault

Open Access Theses & Dissertations

In this research, the adsorption behavior of zeolites with respect to iron (Fe), zinc (Zn), and copper (Cu) has been studied in order to assess its application to heavy metal removal in polluted settings caused by acid mine drainage (AMD). The St. Cloud zeolitic deposit used in this project was characterized using a sieve analysis; the effective diameter and coefficient of uniformity were calculated. Batch studies were performed, and the samples were analyzed using ICP-OES. Batch studies used metal concentrations ranging from 50 mg/L to 650 mg/L. Freundlich, Linear, Langmuir, and BET adsorption isotherms were applied and evaluated to the …

Using Zeolite For Soil Moisture Retention And Salinity Control, Mark Torres

Open Access Theses & Dissertations

There is a great need in the desert southwest United States for exploring ways to save water in agriculture as it accounts for up to 90 percent of water consumption in many western states (USDA 2016). As surface water reaches critical lows the dependence on ground water has increased leading to the need for deeper wells with higher salt concentrations. The studies conducted for this research included using zeolites from the St Cloud Mining Company in Winston, New Mexico to determine the feasibility of using these zeolites to help and retain moisture in zeolite treated soils. The Volumetric Water Content …

Digital Processes And Characterization For Fabricating 3d Rf Devices, Harvey Hing Tsang

Open Access Theses & Dissertations

In this work, co-planar waveguides (CPW) are fabricated and characterized with low temperature 3D printed materials for flexible electronic applications. Laser processing is introduced to reduce heating and cooling times for curing and subtractive manufacturing. CPWs are optimized by varying printing resolution, adjusting curing conditions and shaping conductor profile with a pico-laser. By using acrylonitrile butadiene styrene (ABS) as substrate material and Dupont CB028 as conductive material, a high S21 and low S11 CPW is fabricated. Optimized direct write methods are dispensed onto 3D complex structures to move away from 2.5D style printing and move into true 3D printed antenna …

A Multi-Objective Sustainable Model For Transportation Asset Management Practices, Marketa Vavrova

Open Access Theses & Dissertations

Transportation Asset Management (TAM) practices have gained popularity in the United States and worldwide with the aim to provide the required level of service for the transportation infrastructure network in the most cost-effective manner. However, TAM is a complex decision-making process because many objectives and different perspectives, often producing conflicting goals, must be considered.

This Dissertation presents a Multi-Objective Sustainable (MOS) model to integrate economic, social, and environmental sustainable objectives into TAM decision-making. The objective is to develop a holistic multi-objective asset management approach integrating environmental and social sustainability related performance measures with traditional indicators, such as asset condition and …

Cdte Doped With Zn Grown On Si(111) And Si(211) Using The Closed Space Sublimation Method, Jose Alberto Valdez

Open Access Theses & Dissertations

Cadmium telluride (CdTe) doped with zinc (Zn) has been used for the fabrication of X-ray imaging devices. CdTe allows the device to have the same image quality at a lower X-ray dose. When silicon is used as a substrate for CdTe growth, this reduces the cost and allows the readout circuitry to be fabricated on the same substrate. However, material quality and device performance needs to be addressed since the lattice parameters of CdTe (6.482 Å) and Si (5.431 Å) result in a 19% lattice mismatch.

In this work, CdTe doped with Zn is deposited on Si (211) and Si …

Molecular Dynamics Proxy Applications For Optimizing Performance Of Simulations Under Extreme Conditions, Jayalath Abeywardhana Mudiyanselage Madawa Abeywardhana

Open Access Theses & Dissertations

Exascale performance of scientific application is a prominent goal for the scientific community and computer hardware vendors. As a result, several proxy applications for the widely used scientific codes have been developed with the purpose of testing performance, memory and power consumption issues associated with simulations at the exascale. Co-MD is a proxy application for classical Molecular Dynamics (MD) codes based on the (SPaSM) Los Alamos code.

This work comprises two different but related computational aspects: performance evaluation and optimization of Co-MD (Co-Design Molecular Dynamics) for different computer architectures/execution models, and direct application of SPaSM (Scalable Parallel Short-range Molecular Dynamics) …

Information Entropy Measures Applied To Hierarchial Complex Technical And Socio-Technical Systems, Satya Aditya Akundi

Open Access Theses & Dissertations

A significant increase of Systems-of-Systems (SoS) is currently observed in the social and technical domains. With increasing constituent components, Systems of Systems are becoming larger and more complex. Recent research efforts have highlighted the importance of identifying innovative statistical approaches for analyzing complex systems to better understand how they work. This research is aimed towards developing an Information Entropy based framework to analyze complex technical and social systems. Entropy in terms of information theory can be seen as the expected amount of information observed in an event. A parallel can be drawn between information entropy and system complexity, where, as …

Dielectric Prism Antenna, Jose Antonio Avila

Open Access Theses & Dissertations

3D printing is revolutionizing the development and manufacturing of devices. Currently multi-material 3D printing, like metals plus dielectrics, is in the early stages and not very accessible. This work set out to develop an all-dielectric antenna that could be 3D printed with current widely accessible 3D printing technologies. The antenna developed is an all-dielectric ultra-thin antenna with a simple geometry. The antenna radiates by using total internal reflection and a circulating mode operating as a leaky whispering gallery mode. We are calling the antenna the dielectric prism antenna because it acts like an optical prism. The dielectric prism antenna was …

Effects Of Fabrication Conditions On Mechanical Properties Of Ti-6al-4v Fabricated By Powder Bed Fusion Additive Manufacturing, Paola Azani

Open Access Theses & Dissertations

At the writing of this Thesis, additive manufacturing (AM) also known as 3D printing, has been popularized for its diversity in applications ranging from home and personal use, medical, industrial, consumer products, aerospace, architecture, automotive, military, fashion, food, art and more. Industries taking advantage of the design freedom and complexity offered by AM have exploded the growth of the technologies. Specifically, technologies that process metals using electron and laser beams have been recognized by the aerospace industry as a promising avenue for re-engineered components leading to reduced weight and improved engineering efficiencies for components like engine brackets and nozzles. However, …

High Fidelity Localization And Sensing For Cattle Analytics, Luis Carlos Bañuelos Chacon

Open Access Theses & Dissertations

Global beef production is projected to reach approximately 60 million tons in 2015 and opportunities to increase efficiencies are significant with recent advancements in remote sensing. By economically monitoring the location and conditions of a herd such as feeding patterns, body temperature, heart rate, and other biometric information, the herd performance can now be enhanced through data-driven optimization. Next generation sensors provide high fidelity data on a wide range of measurable properties, and simultaneously, the wide adoption of these sensor systems in many consumer applications is leading to commoditization and reduced cost due to the associated economies of scale. Deploying …

Environmenal Impact Assessment And Removal Of Endocrine Disrupting Compounds In Municipal Wastewater Treatment, Juan C. Bezares-Cruz

Open Access Theses & Dissertations

The presence of compounds of emerging concern (CECs) such as endocrine disrupting compounds (EDCs) and herbicides in municipal wastewater present environmental challenges because conventional treatment systems were not designed to remove such compounds. The removal of Bisphenol-A (BPA), 17?-Estradiol (E2), 17β-Ethinylestradiol (EE2), nonylphenols (NP), and select herbicides and pesticides were investigated in two municipal wastewater treatment plants (WWTP) in El Paso, TX. In addition, the environmental impact of the two municipal wastewater treatment plants was investigated, including the theoretical addition of UV/H2O2. The use of UV/H 2O2 was studied in a UV bench scale pilot unit, and its performance was …

Through-Thickness Reinforcement For Woven Laminates, Alejandra G. Castellanos

Open Access Theses & Dissertations

Fiber reinforced polymer composites have gained popularity in aerospace and naval applications due to their tailorable mechanical properties and high strength-to-weight. Despite these advantages, between the layers of fabric (laminas), there is a resin-rich region known as interlaminar region, with no reinforcement which is very susceptible to damage. Different types of reinforcements have been tested for the interlaminar region. However, all of these methods have proved to decrease the in-plane properties due to damage to the fibers. In this Thesis, a new reinforcement technique with ZnO nanowires is proposed to increase the damage resistance. This Thesis describes the design, manufacturing …

Manufacturing And Characterization Of Energetic Materials, Carlos Alberto Catzin

Open Access Theses & Dissertations

Few products take several years of research effort to be synthesize yet disintegrate in scarcely millionths of a second when used. Despite their short lifespan energetic materials, particularly high explosives, are in demand as never before by the Aerospace, Defense, Energy, Gas, Mining, and Oil Industry for their unique properties. One class of high explosives known as polymer bonded explosives (PBXs) are popularly used in a wide variety of applications ranging from solid rocket propellants to the main explosive charge in conventional ammunitions. A key characteristic behind the popularity of PBXs in comparison to other high explosives is their handling …

Reliable And Secure Scada Framework For Residential Microgrid Communications, Goutham Krishna Chalamasetty

Open Access Theses & Dissertations

Cyber security is one of the major needs for electric power industry like many other industries and organizations. The advancements in technology provide numerous benefits to power industry as well as benefits cyber attackers to perform different cyber-attacks on the industry. Power system is a complex physical entity that deals with power generation, distribution, and transmission. In general, no individual or company or an organization can bear a one hour power cut, which shows the need for reliability in electric power industry.

In order to develop a reliable and secure Supervisory Control and Data Acquisition (SCADA) communication network, this Thesis …

Estimating Air Pollution Concentrations Using Moves-Generated Site-Specific Traffic Emissions, Mayra Consuelo Chavez

Open Access Theses & Dissertations

The research presented here attempts to estimate air pollution concentrations using MOVES and site-specific traffic emissions particularly those emissions surrounding three different air-monitoring stations. The objectives of this research include using MOVES capability to conduct project-level analyses, choosing impact zones to create emissions inventories. Emissions inventories provided by the MOVES model for impact zones within the El Paso county area were used to identify a relationship between air monitoring stations' measured results and emission estimates from a project-level analysis. The research hopes to identify an optimum zone radius that can be used to compare MOVES estimates with air monitoring stations …

Characterization In 2d Sulfides And Graphene Composites For Sensing Applications, Alberto Delgado

Open Access Theses & Dissertations

In this work, we have evaluated 2D layered material composites for opto-electro-mechanical sensing applications. In particular, we have focused on TMDCs and graphite and studied the effects of chemical liquid exfoliation on the structural characteristics of the 2D layered materials, through particle size, x-ray diffraction, Raman and surface area analysis. An approach was developed to combine the solution-processed dispersion with organic and inorganic matrix materials for forming the composites. From Raman Spectroscopy of the ultra-sonicated samples, the I2D/IG>2 for graphite, and for MoS2 the difference between the A1g and E2g peak was 22.85cm-1, consistent with few layer 2D MoS2. …

Mechanically Activated Combustion Synthesis Of Molybdenum Borosilicides For Ultrahigh-Temperature Structural Applications, Alan Alberto Esparza Hernandez

Open Access Theses & Dissertations

The desire to improve the efficiency of power generation gas-turbines has led to a relentless quest for new, ultrahigh-temperature structural materials to replace the current nickel-based superalloys. These materials have reached the maximum allowable operating temperature determined by the melting temperature of these alloys, which is about 1150 °C. These materials could be replaced by molybdenum silicides and borosilicides based on Mo5SiB 2 (T2) phase due to their high melting point and mechanical properties. A major challenge, however, is to simultaneously achieve high oxidation resistance and acceptable mechanical properties at elevated temperatures. One novel approach to improve these properties is …

Combustion Of Novel Thermite Mixtures For Iodine Generation, Sergio Emanuel Guerrero

Open Access Theses & Dissertations

Halogen-containing reactive materials could be used for mitigating the spread of hazardous, active biological microorganisms aerosolized as a result of explosion. The present work exhibits experimental results on the combustion of mechanically alloyed aluminum-iodine (Al-I2) powder mixed with Fe2O3, CuO, MoO3, Bi2O3, and I2O5. Wet mixing was used to prepare the samples, which were then compacted into pellets and ignited with a CO2 laser. A chamber was designed and built to accommodate for combustion and collection of products, and the available laser ignition setup was modified to enable combustion experiments with rapidly burning gas-generating mixtures. High-speed video recording was used …

Numerical Simulation Of The Overlay Tester, Andrea Gutierrez

Open Access Theses & Dissertations

The Overlay Tester (OT) is a relatively new testing procedure that characterizes the cracking resistance of hot mix asphalt (HMA) by evaluating the number of cycles to failure of an HMA specimen. The lack of repeatability and high variability of the results have been a concern to transportation agencies. A careful experimental review of the OT test protocol reveals the complex stress and strain distributions that should be understood in order to improve the certainty associated with the test.

The objective of this Thesis is to present the numerical modeling of the OT test through finite element analysis (FEA). When …

Manufacturing And Mechanics Of Polymer Matrix Composites, Md Shariful Islam

Open Access Theses & Dissertations

Fiber-reinforced composite materials are widely used in the aerospace and automobile industries. Their strength-to-weight and stiffness-to-weight ratios make them suitable to be used in spacecraft, especially as cryogenic tank materials. One of the focus of this dissertation is to investigate the application of woven carbon and Kevlar® fiber composites as cryogenic tank materials. Tensile, bending and short beam shear tests are performed on rectangular specimens at room temperature and after cryogenic exposure (-196°C). It is found that the mechanical properties of these composite materials do not degrade significantly due to cryogenic exposure. It is observed that the failure mode took …

A Novel Approach To Control Corrosion Behaviour On Bio Materials Using Taguchi Method (Design Of Experiments), Sai Dhiresh Kilari

Open Access Theses & Dissertations

In the present work, the Taguchi method, from the design of experiment (DOE) has been used to optimize the dip testing method to test the corrosion resistance of bio degradable materials such as PLA (Polylactic acid)and PCL (Polycaprolactone). A L9 (9) orthogonal array of Taguchi design was used, which involves nine experiments for three parameters (pH, sample, temperature) with three levels was used. Corrosion resistance in various pH change of HCL solution was evaluated by dip tests at various temperatures. Analysis of variance (ANOVA) is performed on the obtained measured data and S/N (signal to noise) ratios. The lower the …

Commercialization Of Cobalt Promoted Molybdenum Disulfide Hydrodesulfurization Unsupported Catalyst, Juan Hilario Leal

Open Access Theses & Dissertations

Catalysis is a key player in the petroleum refining process. Our focus is primarily on the improvement of a commercial HDS (HydroDeSulfurization) hydrotreating catalyst. The commercial catalyst sold today is cobalt promoted molybdenum supported on γ-alumina. Our aim is to work with Porocel Industries LLC to produce an unsupported, cobalt promoted, molybdenum disulfide catalyst by improving on previous work conducted by Dr. Brenda Torres. The catalysts (B3&B5) developed by Dr. Torres were reported to be highly active on real feedstocks and were produced via hydrothermal process. Oxidic Mo, and H2S were used to make an ammonium tetrathiomolybdate precursor that was …

Development Of The Thermal Wire Embedding Technology For Electronic And Mechanical Applications On Fdm-Printed Parts, Daniel Abraham Marquez

Open Access Theses & Dissertations

Additive Manufacturing (AM) has increased in popularity and attracted much attention from many fields such as automotive, aviation, aerospace, and even the fashion industry. Since the early 2000s, Fused Deposition Modeling (FDM) technologies have been the most popular in the AM world ("Wohlers Talk" Popularity of FDM). These technologies have been mainly used for building parts for prototype and structural type of applications such as a fixture for components or a housing for mechanisms.

With the current state of the FDM technologies, the functionality of the parts that are printed are limited to the applications listed before or simply just …

Design Structure Method As Applied To The Structural Organization Of A 5th Genertation Fighter Jet, Israel Michel Michel

Open Access Theses & Dissertations

In current times, the demand for protection against enemies in a volatile geopolitical climate is an increasingly demanding concern. Many countries invest billions of dollars attempting to protect their borders and in fact strive to become the most powerful and dominant war power in the world. As the dollar amount of each country increases, and while other countries seem to always beat each other, the path for innovations and demand is never ending. The complexity of each project continues to grow as they become very sophisticated in their respective field.

In recent decades, itâ??s been proven that whoever reaches the …

Transportation Network Resilience: Evaluation Of Performance Measures, Jessica L. Miramontes

Open Access Theses & Dissertations

The resilience of an urban transportation network is its ability to adapt, absorb, anticipate, and rapidly recover from a disruptive event causing link closures, node closures, and reduced capacity, while providing an acceptable level of service. Several researchers, have performed studies of Transportation Network Resilience (TNR). However, there has not been a clear definition of how to measure or quantify TNR. The objective of this research is to define, quantify and compare the consistency of different measures of TNR and make recommendations to engineers and decision makers. In this research seven proposed parameters have been defined as candidate measures of …

Towards The Scalability And Hybrid Parallelization Of A Spatially Variant Lattice Algorithm, Henry Roger Moncada Lopez

Open Access Theses & Dissertations

The purpose of this research is to design a faster implementation of the spatially variant algorithm that improves its performance when it is running on a parallel computer system.

The spatially variant algorithm is used to synthesize a spatially variant lattice for a periodic electromagnetic structure. The algorithm has the ability to spatially vary the unit cell orientation and exploit its directional dependencies. The algorithm produces a lattice that is smooth, continuous and free of defects. The lattice spacing remains strikingly uniform when the unit cell orientation, lattice spacing, fill fraction and more are spatially varied. This is important for …